Diamond-holding tool



Oct. 6, 1942. J. DINHOFER DIAMOND-HOLDING TOOL Filed .April 17, 1942 .INVENTOR.

flinkofer ikzzom Patented Oct. 6, 1942 UNITED STATES PATENT OFFICE DIAMOND-HOLDING TOOL Julius Dinhofer, New York, N. Y.

Application April 17, 1942, Serial No. 439,359

1 Claim.

This invention relates to diamond-holding tools of the character usually employed for grinding wheel dressing purposes and for other uses, an example of such tool being shown in my Patent No. 2,275,511.

The object of the present invention is to provide a tool used for holding a prepared diamond, and particularly a diamond of octahedral or bipyramidal shape, and the primary object of the present invention is to provide means in a holder of this character, by which particles of grit, dirt and the like finding their way between portions of the holder, will be discharged from between the parts, thereby retaining the parts of the holder indefinitely in properly operative position relative to one another.

Another object of the invention is to provide in a tool of this character means by which the tool may be kept as cool as possible in operation and kept free from dirt, dust and collected particles of grit.

These and numerous other advantages are attained by the structure, a more particular description of which will appear hereinafter and be set forth in the appended claim.

In the accompanying drawing forming a part thereof, Fig. 1 is a vertical sectional view of a holder constructed in accordance with the invention; Fig. 2 is a perspective view of the diamond accommodated in said holder; Fig. 3 is a plan view of the holder and diamond; Fig. 4 is a plan view of the holder, with the cap and diamond removed,v and showing the seat upon which the lower pyramidal portion of the diamond rests; and Fig. 5 is a side view of the holder.

In the drawing, I indicates the body of the holder which may be of any suitable shape and is illustratively shown in the form of a cylindrical rod having a reduced portion 2 provided with a hexagonal end part 3, having a central opening 5. The end of the hexagonal portion 3 is formed with four inclined surfaces 4 which co-operate in the formation of an angular seat upon which the lower pyramidal portion of the diamond 6 rests, as clearly seen in Fig. 1. The end portion of the holder, in which the seat 4 is located, is provided with four radial slots III, which lend resiliency to this portion of the holder. The diamond 6, shown in perspective in Fig. 2, is preferably of octahedron shape and is thus bipyramidal and has six pointed ends, two of which are respectively shown at I and 8. It will be obvious that the diamond may be positioned in any one of several ways in the holder to cause any one of its six pointed ends to be projected out of the holder as indicated at 8 in Figs. 1 and 5. The diamond is clamped upon the seat 4 by means of a clamping member or cap H which fits over and encloses the hexagonal end portion 3 of the holder, said cap member being provided with an end wall in which is formed a substantially square opening I2, the edges of the same being inclined to fit over and engage against the inclined walls of the upper pyramidal portion of the diamond in the manner clearly shown in Fig. 1.

The side wall of the cap II is formed with a plurality of spaced openings 13, four of said openings being shown, although it will be understood that this number may be increased or decreased. Since the inside of the cap H is cylindrical and the portion 3 of the holder over which the cap fits is hexagonal, it will be obvious that the cap has its inside wall surfaces spaced from the faces of the hexagonal portion 3. Thus, any grit, dirt, or lubricating liquids making their way between the diamond 6 and the inside of the cap will proceed between the hexagonal surface 3 and the inner surface of the cap II to be discharged out of the openings l3 in the cap.

Through this arrangement of openings I 3, in co-operation with the hexagonal or polygonal shaping of the portion 3 of the holder over which the cap fits, dust, dirt and grit cannot build up within the holder to dislodge or shift the position of the respective parts of the same to thus cause displacement of the diamond or permit it to chatter or move in the holder. It has also been found that through the arrangement of openings I 3, the inner portion of the holder is accessible to atmosphere and is kept cool. Accordingly, the openings i3, while acting as discharge openings for grit or other foreign materials, also serve as ventilating openings to keep the tool cool. The shape of the openings l3 will be seen in Fig. 5 where it will be noted that the same are more or less pear-shaped or widened gradually at their ends remote from the diamond. It has been found that this type of gradually widening opening is effective in permitting a complete discharge of grit or other materials entering between the parts of the holder.

The cap I I is adjusted to clamp the diamond securely on the seat 4 by means of an internally threaded adjusting ring 22, the same being received upon the threaded portion 23 of the holder. One end of the cap II is formed with a ramally extending flange 20 taking under an inturned flange portion 2| on the adjusting ring 22 so that when the ring 22 is rotated, it will Y ditions of use.

operate to cause the cap H to clamp the diamond 6 tightly down upon the seat 4. To prevent rotative movement of the cap during such adjustment, the side wall of the same is provided with diametrically opposite slots I! which extend over radially projecting pins l9 formed on the hexagonal portion 3 of the holder. To prevent the adjusting ring 22 from shifting its position once it has been set, a set-screw 24 is provided.

In assembling the tool, the diamond is first placed upon the seat 4 and the cap II is then placed over the diamond with the upper pyramidal portion of the diamond extending through the square opening l2 in the top of the cap. This exposes the pointed termination 8 of the diamond out of the holder and the lower pointed termination 1 extends down into the central opening 5 in the holder. By rotation of the locking ring 22, the cap is caused to clamp the diamond firmly down upon the seat 4 and hold it during all con- Once the cap is tightened down, the set-screw 24 is then tightened to hold the ring 22 against rotative shifting movement. It will be understood that the diamond may be shifted whenever required to utilize any of the six points of the same for wheel dressing or other purposes. Under all conditions of use, it will be found that through the employment of the openings [3, and the co-operating polygonal portion 3 of the holder, dust, dirt, grit and other accumulations will not build up inside of the holder but will be discharged through the side openings. The tool will also remain cool under severe working conditions and. will have exceed.- ingly long life.

While I have shown the portion 3 of the holder as being hexagonal or polygonal, it will be understood that the same may be made in other shapes, the prime requisite being that the same be spaced from the interior of the cap I l to permit the passage of grit out of the openings I3 and to allow entry of air to cool the interior parts of the holder.

What I claim is:

In a diamond-holding tool, a holder provided at one end with a seat for receiving a diamond, a cap fitted over said end for engaging the diamond and holding it on the seat, the cap being internally cylindrical, a threaded portion on the holder remote from the seat for adjustably receiving the cap, the side surface of the holder from the seat to the threaded portion being polygonal to thereby provide spacing between the internally cylindrical surface of the cap and said polygonal surface of the holder, the side wall of the cap being provided with grit-discharge and ventilating openings in communication with the space between the cap and polygonal surface of the holder.

JULIUS DINI-IOFER. 

